-\section publications Selected publications
-
-When citing SimGrid, the prefered reference paper is <i>Scheduling
-Distributed Applications: the SimGrid Simulation Framework</i>, even if it's
-a bit old now. We are actively working on improving this.
-
-\subsection simulation About simulation
-
-\li <b>Scheduling Distributed Applications: the
- SimGrid Simulation Framework</b>\n
- by <em>Henri Casanova and Arnaud Legrand and Loris Marchal</em>\n
- Proceedings of the third IEEE International Symposium
- on Cluster Computing and the Grid (CCGrid'03)\n
- Since the advent of distributed computer systems an active field
- of research has been the investigation of scheduling strategies
- for parallel applications. The common approach is to employ
- scheduling heuristics that approximate an optimal
- schedule. Unfortunately, it is often impossible to obtain
- analytical results to compare the efficacy of these heuristics.
- One possibility is to conducts large numbers of back-to-back
- experiments on real platforms. While this is possible on
- tightly-coupled platforms, it is infeasible on modern distributed
- platforms (i.e. Grids) as it is labor-intensive and does not
- enable repeatable results. The solution is to resort to
- simulations. Simulations not only enables repeatable results but
- also make it possible to explore wide ranges of platform and
- application scenarios.\n
- In this paper we present the SimGrid framework which enables the
- simulation of distributed applications in distributed computing
- environments for the specific purpose of developing and evaluating
- scheduling algorithms. This paper focuses on SimGrid v2, which
- greatly improves on the first version of the software with more
- realistic network models and topologies. SimGrid v2 also enables
- the simulation of distributed scheduling agents, which has become
- critical for current scheduling research in large-scale platforms.
- After describing and validating these features, we present a case
- study by which we demonstrate the usefulness of SimGrid for
- conducting scheduling research.
-
-
-\li <b>A Network Model for Simulation of Grid Application</b>\n
- by <em>Henri Casanova and Loris Marchal</em>\n
- \anchor paper_tcp
- In this work we investigate network models that can be
- potentially employed in the simulation of scheduling algorithms for
- distributed computing applications. We seek to develop a model of TCP
- communication which is both high-level and realistic. Previous research
- works show that accurate and global modeling of wide-area networks, such
- as the Internet, faces a number of challenging issues. However, some
- global models of fairness and bandwidth-sharing exist, and can be link
- withthe behavior of TCP. Using both previous results and simulation (with
- NS), we attempt to understand the macroscopic behavior of
- TCP communications. We then propose a global model of the network for the
- Grid platform. We perform partial validation of this model in
- simulation. The model leads to an algorithm for computing
- bandwidth-sharing. This algorithm can then be implemented as part of Grid
- application simulations. We provide such an implementation for the
- SimGrid simulation toolkit.\n
- ftp://ftp.ens-lyon.fr/pub/LIP/Rapports/RR/RR2002/RR2002-40.ps.gz
-
-
-\li <b>MetaSimGrid : Towards realistic scheduling simulation of
- distributed applications</b>\n
- by <em>Arnaud Legrand and Julien Lerouge</em>\n
- Most scheduling problems are already hard on homogeneous
- platforms, they become quite intractable in an heterogeneous
- framework such as a metacomputing grid. In the best cases, a
- guaranteed heuristic can be found, but most of the time, it is
- not possible. Real experiments or simulations are often
- involved to test or to compare heuristics. However, on a
- distributed heterogeneous platform, such experiments are
- technically difficult to drive, because of the genuine
- instability of the platform. It is almost impossible to
- guarantee that a platform which is not dedicated to the
- experiment, will remain exactly the same between two tests,
- thereby forbidding any meaningful comparison. Simulations are
- then used to replace real experiments, so as to ensure the
- reproducibility of measured data. A key issue is the
- possibility to run the simulations against a realistic
- environment. The main idea of trace-based simulation is to
- record the platform parameters today, and to simulate the
- algorithms tomorrow, against the recorded data: even though it
- is not the current load of the platform, it is realistic,
- because it represents a fair summary of what happened
- previously. A good example of a trace-based simulation tool is
- SimGrid, a toolkit providing a set of core abstractions and
- functionalities that can be used to easily build simulators for
- specific application domains and/or computing environment
- topologies. Nevertheless, SimGrid lacks a number of convenient
- features to craft simulations of a distributed application
- where scheduling decisions are not taken by a single
- process. Furthermore, modeling a complex platform by hand is
- fastidious for a few hosts and is almost impossible for a real
- grid. This report is a survey on simulation for scheduling
- evaluation purposes and present MetaSimGrid, a simulator built
- on top of SimGrid.\n
- ftp://ftp.ens-lyon.fr/pub/LIP/Rapports/RR/RR2002/RR2002-28.ps.gz
-
-\li <b>SimGrid: A Toolkit for the Simulation of Application
- Scheduling</b>\n
- by <em>Henri Casanova</em>\n
- Advances in hardware and software technologies have made it
- possible to deploy parallel applications over increasingly large
- sets of distributed resources. Consequently, the study of
- scheduling algorithms for such applications has been an active area
- of research. Given the nature of most scheduling problems one must
- resort to simulation to effectively evaluate and compare their
- efficacy over a wide range of scenarios. It has thus become
- necessary to simulate those algorithms for increasingly complex
- distributed, dynamic, heterogeneous environments. In this paper we
- present SimGrid, a simulation toolkit for the study of scheduling
- algorithms for distributed application. This paper gives the main
- concepts and models behind SimGrid, describes its API and
- highlights current implementation issues. We also give some
- experimental results and describe work that builds on SimGrid's
- functionalities.\n
- http://grail.sdsc.edu/papers/simgrid_ccgrid01.ps.gz
-
-\subsection research Papers using SimGrid results
-
-\li <b>Optimal algorithms for scheduling divisible workloads on
- heterogeneous systems</b>\n
- by <em>Olivier Beaumont and Arnaud Legrand and Yves Robert</em>\n
- In this paper, we discuss several algorithms for scheduling
- divisible loads on heterogeneous systems. Our main contributions
- are (i) new optimality results for single-round algorithms and (ii)
- the design of an asymptotically optimal multi-round algorithm. This
- multi-round algorithm automatically performs resource selection, a
- difficult task that was previously left to the user. Because it is
- periodic, it is simpler to implement, and more robust to changes in
- the speeds of processors or communication links. On the theoretical
- side, to the best of our knowledge, this is the first published
- result assessing the absolute performance of a multi-round
- algorithm. On the practical side, extensive simulations reveal
- that our multi-round algorithm outperforms existing solutions on a
- large variety of platforms, especially when the
- communication-to-computation ratio is not very high (the difficult
- case).\n
- ftp://ftp.ens-lyon.fr/pub/LIP/Rapports/RR/RR2002/RR2002-36.ps.gz
-\li <b>On-line Parallel Tomography</b>\n
- by <em>Shava Smallen</em>\n
- Masters Thesis, UCSD, May 2001
-\li <b>Applying Scheduling and Tuning to On-line Parallel Tomography </b>\n
- by <em>Shava Smallen, Henri Casanova, Francine Berman</em>\n
- in Proceedings of Supercomputing 2001
-\li <b>Heuristics for Scheduling Parameter Sweep applications in
- Grid environments</b>\n
- by <em>Henri Casanova, Arnaud Legrand, Dmitrii Zagorodnov and
- Francine Berman</em>\n
- in Proceedings of the 9th Heterogeneous Computing workshop
- (HCW'2000), pp349-363.